I. Field of the Invention
This invention is directed to the field of wireless communications. More specifically, this is invention is directed to the use, in a wireless communication system, of a central base station and one or more remote base stations that include transmit power control.
II. Description of Related Art
Wireless communication is an ever growing industry. Wireless communication devices are applied in numerous applications, such as cellular communications, wireless (computer) networking, data delivery, and any number of other uses. For applications that employ bi-directional communication, such as cellular communications and wireless networking, signals are sent and received from at least two points. In the context of cellular communications, signals are normally communicated between a base station (e.g., a radio tower and associated controller) and one or more mobile devices (e.g., cellular phones, wireless personal digital assistants, etc.).
Such base stations currently include essentially all of the functionality for implementing a radio link with the mobile stations, which are typically implemented in one or more sectors (e.g., geographic coverage areas). Current base stations assign Walsh codes, determine (pseudo-noise) PN offsets, assign/define cell sectors and channels for communication traffic and regulate transmission power for the forward link (to the mobile) and reverse link (from the mobile) signals in cooperation with the mobile station(s). The use of Walsh codes and PN offsets is known and, for the sake of brevity, will not be described in detail here. Briefly, however, the use of Walsh codes and PN offsets allows for each of the sectors of a cell site and geographically proximate cell sites to use the same carrier channel frequency pairs. Additionally, such base stations also communicate with (or include) a base station controller to facilitate communication with a mobile switching center, etc. For a code division multiple access wireless communication system (CDMA), these aspects are described in further detail in Telecommunications Industry Association (“TIA”) standards IS-95A and IS-95B, which are both incorporated herein by reference in their entirety. CDMA is also described in the International Telecommunications Union (“ITU”) IMT-2000 series of standards, which are all incorporated herein by reference in their entirety. CDMA is further described in the TIA IS-2000 series of standards, which are all incorporated herein by reference in their entirety. The IS-2000 series of standards are commonly referred to as CDMA2000.
In wireless communication systems, it is not uncommon to have a certain geographic areas that have high communication traffic volume during certain time periods and low volume during other time periods (e.g., an urban business district during normal business hours as compared to evenings and weekends). Further, there may be geographically adjacent or nearby areas that have opposite communication traffic volume patterns (e.g. high traffic volume during the low traffic volume periods of the first area and low traffic volume during the high traffic volume time periods of the first area, such as a suburban residential area neighboring the urban business center.)
During time periods when communication traffic is low in a certain geographic area, the resources of any base stations serving those areas may be mostly idle during such times. Such inefficient use of base station resources is undesirable because implementing and operating a base station is costly. Therefore, it is desirable to more effectively utilize the resources of such base stations in order to reduce the overall costs associated with implementing and operating a mobile telecommunication system.